The present invention relates to a storage control system and a storage control method. In particular, it relates to a storage control system connected to host systems and storing, according to a RAID method, data transmitted between itself and the host systems in hard disk drives (HDDs) arranged in arrays, and a storage control method for the storage control system.
This type of the storage control system is known as one having: drives containing rotatable-type storage devices for storing data; and storage controllers existing between the drives and host systems and controlling data transmission therebetween. Such a storage control system is disclosed in Japanese Patent Laid-Open Publication No. H11-191037.
The above publication describes that, when a failure occurs in a disk drive in an ECC group (RAID group) and prohibits the operation of the disk drive, the entire data in the faulty drive is recovered based on the data in the remaining drives in the group and copied to spare disk drive(s) (collection copy).
Japanese Patent Laid-Open Publication No. 2002-297322 discloses a storage control system having spare disk drives. With this storage control system, in the case of failure in any one of disk drives constituting the RAID groups, data is recovered based on data in the remaining disk drives in the RAID group so that the RAID operation mode recovers from a degeneration mode to a normal access mode in which all the disk drives constituting the RAID operate.
Japanese Patent Laid-Open Publication H6-139027 discloses a storage control system having: disk array controller(s); disk drives arranged in arrays, connected to the disk array controller(s) via drive interface(s), and storing a plurality of pieces of data; and data backup device(s) for backing up the data stored in the disk drives. In this storage control system, some of the disk drives are used as spare disk drives and the rest are used as data/parity disk drives, and when a failure occurs in a data/parity disk drive, a spare disk drive is set as a data/parity disk drive in place of the faulty data/parity disk drive.
With these conventional storage control systems, when a failure occurs in a disk drive, they commence the collection copy and a maintenance person who is informed of that commencement checks the completion of the collection copy and replaces the faulty disk drive with a normal one. After the replacement, the maintenance person gives a command to the storage control systems to copy back the storage information in the spare disk drives to the new disk drive.